The decimeter is a unit of length between meters and centimeters, English is decimetre, abbreviated as DM, one decimeter is equal to ten centimeters.
cm is an abbreviation for centimeter, which is used to represent centimeter. mm is an abbreviation for millimeter, which is used to represent millimeters.
Decimeter is one of the international length units, 10 decimeters is equal to 1 meter, China did not have the length of the decimeter in ancient times, but as early as the Qin Dynasty, China's measurement method has been accurate to the centimeter level, from the terracotta archaeological analysis can prove this.
After the development of modern natural science, cultural exchanges between countries need a unified unit of measurement to facilitate conversion, so the metric unit was born, the metric unit was born in Fa, so it was originally defined as one ten-millionth of the distance from the earth's equator to the North Pole on the meridian through Paris.
In order to calculate more accurately, the meter is divided into decimal systems, and units such as decimeters (dm), centimeters (cm), and millimeters (mm) appear, which are one-tenth of the former. With the advancement of science and technology, in order to meet the more scarce needs of onlookers, microns (abbreviated as m, thousandths of a millimeter) and nanometers (abbreviated as nm, thousandths of a millimeter) and nanometers (abbreviated as nm, ten-thousandths of a millimeter) have been formulated.
Length measurement is the basis of scientific development, the first contact found these English abbreviations difficult to remember, but fortunately, the number is relatively small, after repeated use, it is still more convenient and fast to remember.